Controlling mechanism for steam engines and the like



G. HOLMES Oct. 14, 1930.

CONTROLLING MECHANISM FOR STEAM ENGINES AND THE LIKE Filed Oct. 19, 1925 INVENTOH. GRANT H0 MES.

/4 TTOR/VE Y Patented Oct. 14. 1930 mUNIT E D STATES PATENT OFFICEF r 7 ANT Homvrns, or nANvrLLE, ILLINOIS, ASSIGNOR roman MARION COMPANY, OF MARION, OHIO, A CORPORATION OF OHIO CONTROLLING MECHANISM FOR STEAM ENGINES AND THE LIKE Application filed October 19, 1925. Serial No. 6 3,508.

This inventionrelates to a controlling mechanism for steam engines and the like and one object .of the invention is to provide automatically controlled means for causing the gradual acceleration and deceleration of the engine; and, further, to cause the acceleration and deceleration at a predetermined rate. ,y

*A further object of the invention is to provide sucha mechanism which may be operated in conjunction with the usual reversingvalve of an engine and will automaticallyretard the operation of the throttlevalve so as to cause the gradual admission of steam to the reversing valve.

A further object of the invention is to pro.- vide such a mechanism which will be simple 7 in its construction and operation and which can be easily interposed in thesteam line of an ordinary steam engine.

Other objects of'the invention will appear as the mechanism is described in detail.

In the accompanying drawings Fig. 1 is a side elevation of a portion ofa steam engine, showing my invention applied thereto; Fig.

i 2 is a longitudinal sectional view taken centrally through the throttle valve and its controlling mechanism; and Fig. 3 is a transverse sectional view taken on the line 3-3 of Fig. 2. i

In these drawings I have illustrated one embodiment of my invention and have shown the same in conjunction with a throttle valve of a particular kind but it will be understood that the invention may take various forms and may be applied to throttle valves of different kinds.

- I have here shown the inventionas applied to asteam engine, one of the cylinders of which is shown at l and which comprises a reversing valve 2 which may be of the usual or ,any suitable character. This reversing valve is connected with the steam supply line 3 and is actuated by means of a valve rod4 which, in the present instance, extends beyond that end thereof opposite the supply 7 line 3. This rod is'connected by means of a -"link5 with a lever 6' which is pivotally STEAM SHOVEL or the like, by means of which the engineer may manipulate the reversing valve.

Interposed in the steam supply line 3, between the reversing value and the source of steam supply, is a throttle valve which is here shown as comprising a housing 8 having within the same a steam chamber 9 which is provided with an inlet port 10 connected with the source of steam supply and at its other side with an outlet port 11 connected with the reversing valve. Arranged within the housing is a cylindrical valve seat 12 which is interposed between the chamber 9 and the outlet port 11 so that the steam must pass through this valve seat, in order to reach the reversing valve. As here shown, the valve seat overlies the inner end of the port 11 and is provided with two passageways or ports 13 which connect the interior thereof with the outlet port 11. The ports 13 extend circumterentially of the valve seat and the lower portions thereof are in the form of slots which merge at their upper ends into grooves 14; extending about the upper portion of the valve seat. Mounted in the cylindrical valve seat is a valve piston which, in the present instance, comprises two hollow cylindrical portions 15 connected by means of a spider 16 with .aihub portion 17. The two parts of the valve piston are so arranged that when the valve is in its normal or closed position these 'parts will overlie and close the respective circumferential ports 13, thus preventing the passage of steam from the chamber 9 to the piston shall extend obliquely to the axis of the piston, as shown at 18, thus causing the severalparts of each circumferential port to be'successively uncovered and covered as the valve is moved to itsopen and closed positions.

T he valve piston may be operated in any suitable manner but preferably it is power operated and I have here shown it as connected by inea-nsof a rod 19 with a pistonQO which is mounted ina steam cylinder 21 arranged in axial alinement with the cylindrical valve seat. The piston is so arranged in the cylinder 21 that when the valve piston is in its.

lever 21 which is pivotally mounted between its ends to a fixed support, such as a stud 25 projecting from the outer head of the cylinder 21. The lower end of the lever 24 is connected' with the link 5 by means of which the reversing valve 2 is connected with the operatingrod 7, so that when the reversing valve is operated the D-valve 32 will also be operated to admit steam to the cylinder 21 on oneside or the other of the piston 20, according to the direction in which the reversing valve is moved. The pressure of the steam on the piston will move the same toward that end of the cylinder opposite that to which the steam was admitted and because of its connection with the valve pistonaxial movement will be imparted to that piston and the ports 13 opened to permit the flow of steam to the reversing valve. 1

In order to insure a slow movement of the valve piston and a consequent gradual acceleration and deceleration of the engine I have provided means for automatically retarding the movement of the valve piston and for causing this movement to be imparted to the valve piston at agiven rate of speed. To this end I- have connected the valve piston, by means of a rod 26, with a piston 27 which is mounted in a second cylinder 28 also preferably arranged in axial alinement with the cylindrical valve seat and adapted to contain a fluid, such as oil. The

piston 27 is so arranged with relation to the valve piston that when the valve piston is in its closed position the piston 27 will be arranged substantially midway between the ends of the cylinder 28- The end portions: of the cylinder 28, on the opposite sides of the piston 27, are connected one to the other by means of a by-pass 29 through which the oil or other fluid must flow as the piston moves toward one end or the other of the cylinder, and obviously the piston 27 can move in the cylinder no faster. thanthe oil can flow from one end thereof to the other. Consequently the steam acting on the piston 20 can move the valve piston at a speed no greater than that at which the fluid is transferred from end of the cylinder 28 to the other. Inasmuch as the oil or other fluid will flow through the bypass at a uniform rate of speed the capacity of the by-pass also determines the speed of movement of the piston'valve and the rate of acceleration of the engine. If desired, means may be provided for varying the capacity of the by-pass, by restricting the flow of the fluid therethrough. In the present instance, a turn plug valve 30 is interposed in the by-pass between the ends thereof and by adjusting this valve the passageway may be more or less restricted and the rate of flow of the fluid regulated. Interposed between the piston 27 and .the respective ends of the cylinder 28 are springs 31 one or the other of which will be placed under compression when movement is imparted to the piston 27 and the spring which has thus been compressed will serve to restorev the piston 27, and consequently the valve piston 15, to their normal positions when the steam pressure on the piston 20 is relieved. Obviously the return movement of the piston 27 also displaces the fluid in the cylinder 28 and the speed of the return moveof and it will be apparent that 'when the actuating rod 7 is manipulated to move the reversing valve in one direction or the other, according to the direction in which the engine is to be operated, the valve 22 of the cylinder 21 will be moved in a corresponding direction so as to admit steam on one side of the'piston 20. The pressure of this steam tends to move the piston 20, the valve piston 15and the retarding piston 27 all simultaneously in the same direction because they are all rigidly connected one to the other. The movement of the piston 27 being retarded bythe restricted flow of the oil through the by-pass 29 serves also to retard the movement of the valve piston, thus causing the throttle valve to be opened slowly and at a speed determined by the capacity of the by-pass. During this; movement of the vpiston 27 one of the springs 31 will be compressed and when thereversing valve is restored toits idle or closed position the valve 22 will be restored to its normalposition, in which both ends of the cylinder 21 will be connected with the exhaust, thereby relieving the piston 20 of the steam pressure and permitting the spring 31 which has been compressed'to return the retarding piston 27 and the connected parts to normal position, thisfmovement also be ing retarded by the flow of the'oil through the by-pass 29 which results in the gradual decelerationof the engine at a pre-determined rate. V i

r In the organization here illustrated the cylinders 21 and 28 are rigidly secured to the housing of the throttle valve so that the mechanism as a whole, constitutes a single unit which may be interposed in and supported by the steam. supply pipe 3. It will embodiment of my invention I Wish it to be understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention,

what I claim as new and desire to secure by Letters Patent, is:

1. In a device for automatically control ling the admission of steam to an engine to gradually accelerate and decelerate the same,

a throttle valve comprising a valve casing having inlet and outlet ports to be connected in the steam line leading to said engine and having a cylindrical valve seat interposed between said ports, and a valve piston slidably mounted in said valve seat, a cylinder mounted on and supported by one side of said valve casing in line with said valve seat. a piston mounted in said cylinder and rigidly connected with said valve piston, a valve to 7 control the admission of steam to said cylingine, and a valve 1n said valve casmg, a fluid operated device der, a second cylinder mounted on and supported by the opposite side of said valve casing and arranged in alinement with said valve seat. and a piston mounted in said second cylinder and rigidly connected with said valve piston, said second cylinder having means to permit of a restricted flow of fluid from one side of the piston to the other side thereof.

2. In a device for automatically controlling the admission of steam to an engine to gradually accelerate and decelerate the same,

a throttle valve comprising a valve casing interposed in the steam line leading to the enmember movably mounted mounted on and supported by said valve casing and connected with said valve member, manually actuated means to control the ad mission of fluid to said fluid operated device, and a fluid controlled retarding device mounted on and supported by said valve casing and connected with said valve member to retard its movement by said fluid operated device.

In testimony whereof, I aflix my signature hereto.

GRANT HOLMES. 

